In today's automotive engine systems, there is an increased demand for low cost, direct injection. In common rail injection systems, the fuel is delivered by means of a high pressure pump located in an engine compartment to a fuel rail which serves as a pressurized storage reservoir for the fuel. The fuel is under high pressure in the fuel rail and can be injected directly into the cylinders via injectors connected to the rail.
Typical direct injection, high pressure pumps of the type disclosed in U.S. Patent Application Publication No. 20100242922 A1 have a solenoid valve at the inlet as a flow control valve to control flow rate through the pump. The solenoid valve is complicated, requires an electrical connection to a power source, as well as a complex control system, and adds cost to the high pressure pump.
There is a need for a pressure operated, mechanical flow control valve that is simple in construction, eliminates electronic control and delivers fuel under a single pressure to a fuel rail.